As the field of wireless communications develops, various wireless communication standards or protocols continue to be deployed. At a given location, it is becoming increasingly likely that one or more wireless networks are available for use, accessible via one of a variety of communication protocols. For example, Wi-Fi, Wi-MAX, CDMA, GSM, UMTS, and other communication protocols are currently available for use in connecting with different networks in locations worldwide. Moreover, in some locations, a choice of wireless networks operating with multiple communication protocols may be available.
To facilitate mobility of wireless devices, or to take advantage of the availability of multiple communication protocols in a given location, is often desirable to provide wireless communication devices operable using more than one wireless communication protocol. For example, a “dual mode” device capable of communication using both CDMA and GSM can be useful in diverse geographical areas where the different protocols are used. As another example, a device capable of communication using both CDMA and Wi-MAX may take advantage of the benefits of each protocol, and may select between protocols when both are available. Challenges for creating such multi-mode devices include cost, size, performance, and power constraints.
One approach to providing a wireless device capable of using more than one protocol is to utilize reconfigurable radio modules within the wireless device. Such modules may contain common hardware components which can be reconfigured as required to operate according to a desired communication protocol, for example as described in U.S. Pat. No. 7,035,596. However, such generic, reconfigurable components typically behave poorly with respect to indicators such as performance and cost. In addition, reconfiguration operations may require additional time, further reducing overall performance of the wireless device.
Another approach is to incorporate plural single-mode wireless communication modules into a wireless communication device. For example, multi-mode wireless handsets have been proposed which provide seamless hand-off of voice sessions between Wi-Fi and cellular networks. Use of such single-mode wireless communication modules may provide a cost savings due to their relative simplicity and availability in the marketplace. However, incorporating plural single-mode communication modules into a common wireless device may cause operating problems when there are power limitations. For example, operation of more than one wireless communication module at a time typically requires increased power, which may be above rated power limitations, thereby causing functional problems and/or device damage. Such limitations are apparent, for example in wireless adapters having a universal serial bus (USB™) interface, where simultaneous operation of plural single-mode wireless communication modules may result in a current draw to the wireless adapter greater than the maximum rated current specified for the associated USB™ bus.
Therefore there is a need for an apparatus providing plural wireless communication capabilities that is not subject to one or more limitations in the prior art.
This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.